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AIR CONDITIONING
24-23
The system must be completely discharged before
opening any fitting or connection in the refrigeration
system. Open fittings with caution even after the sys-
tem has been discharged. If any pressure is noticed
as a fitting is loosened, allow trapped pressure to
bleed off very slowly. Use a suitable tube bender
Tool C-3362 when bending the refrigerant lines to
avoid kinking. Never attempt to rebend formed lines
to
fit.
Use the correct line for the installation you are
servicing.
A good rule for the flexible hose lines is keep the
radius of all bends at least 10 times the diameter of
the hose. Sharper bends will reduce the flow of
re-
frigerant. The flexible hose lines should be routed so
that they are at least 3 inches from the exhaust mani-
fold. It is good practice to inspect all flexible hose
lines at least once a year to make sure they are in
good condition and properly routed.
"0" rings and fittings must be in good condition.
The slightest burr or foreign material may cause a
leak. "0" rings and fittings must be coated with re-
frigerant oil to allow the connections to seat squarely
and to be tightened evenly to the proper torque. Fit-
tings which are not oiled with refrigerant oil are al-
most sure to leak (Fig. 23).
The use of proper wrenches, Tools (2-3358 and C-
3363, when making connections is very important.
Improper wrenches or improper use of wrenches can
damage the fittings. Always use two wrenches when
loosening or tightening tube fittings to prevent dis-
torting of lines and components.
The internal parts of the refrigeration system will
remain in a state of chemical stability as long as pure-
moisture-free refrigerant 12 and refrigerant oil is
used. Abnormal amounts of dirt, moisture or air can
upset the chemical stability and cause operational
troubles or even serious damage if present in more
than minute quantities.
When it is necessary to open the refrigeration sys-
tem, have everything you will need to service the sys-
tem ready so that the system will not be left open any
longer than necessary. Cap or plug all lines and
fit-
tings as soon as they are opened to prevent the en-
trance of dirt and moisture. All lines and components
in parts stock should be capped or sealed until they
are ready to be used.
All tools, including the refrigerant dispensing man-
ifold, the gauge set manifold and test hoses should be
kept clean and dry.
The special refrigeration oil supplied for the sys-
tem is as clean and dry as it is possible to make
it.
Only refrigeration
oil
should be used in the system
or on the fittings and lines. The oil container should
be kept tightly capped until it is ready for use, and
then tightly capped after use to prevent entrance of
dirt and moisture. Refrigerant oil will quickly absorb
any moisture with which it comes in contact.
COMPRESSOR DRIVE BELT ADJUSTMENT
Satisfactory performance of the air-conditioning
system is dependent upon drive belt condition and
tension. If the proper tensions are not maintained,
belt slippage will greatly reduce air-conditioning per-
formance and drive belt life. To avoid such adverse
effects, the following service procedure should be fol-
lowed:
(1)
Any belt that has operated for a minimum of a
half-hour is considered to be an "in use" belt. Adjust
air-conditioning drive belts at the time of new-car
preparation. Using the torque method, tension should
be 55 foot-pounds for models equipped with the 318
cubic-inch engine; 40 foot-pounds for all other V-8
engines: 25 foot-pounds for the 6 cylinder engine.
(2)
Measure the drive belt tension at regular serv-
ice intervals, using the torque method, and readjust
as needed.
(3) On all new-belt installations, new-belt tension
specifications should be used when the belt is first in-
stalled to obtain proper tension. Thereafter, these
replacement belts should be serviced according to the
above procedure. Always replace belts in pairs if
so
equipped, otherwise the old belt will have insufficient
tension and the load will be primarily on the new
belt. Proper tension for new belts is 75 foot-pounds
for the 318 cubic-inch engine;
60
foot-pounds for all
other V-8 engines; 35 foot-pounds for the 6 cylinder
engines.
ANTIFREEZE RECOMMENDATIONS
The Air-conditioning System requires the engine's
cooling system to be protected to +15"F. with a
permanent type antifreeze for summer operation.
This is to prevent freezing of the coolant in the heat-
er core.
In the springtime, after the winter's operation with
the cooling system protected with permanent-type
antifreeze for the temperatures of the area, it is sug-
gested the system be drained and flushed out with
water. When draining, flushing and refilling, have the
temperature control lever in the extreme hot posi-
tion so the heater core is drained, flushed and refilled.
Install a gallon of permanent type antifreeze in the
system, and add enough water to fill the system.
Do not re-use the
old
antifreeze.
The permanent
type antifreeze does not lose its antifreeze qualitites
during the winter season operation, but the chemical
inhibitors for rust and corrosion prevention are
weakened and finally exhausted by extended use. Do
not add new inhibitor to used antifreeze in hope of
revitalizing the used antifreeze.
The chemical inhibitors come in various chemical
compositions, some are compatible, some neutralize
each other, and some form violent reactions to each
other causing foaming and other undesirable reac-
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